This invention relates generally to the field of heat treatment of textile fabrics, and more particularly to an improved means and method for live steam heat treatment of upholstered seats for vehicles and similar articles as they pass along a production line conveyor.
In the manufacture of upholstered articles, typically seats for vehicles, the assembly of the workpiece has become highly automated, wherein mechanical means is provided to install padding and the outer upholstered shell of the seat. As the seats pass down a conveyor line, wrinkles in the fabric caused by the fact that the material forming the outer surface is not in planar condition is typically manually detected by individual workers a who employ a known type of electrically powered steam iron which directs steam directly to the wrinkled area, following which the workpiece continues to travel down the assembly line. Because the operation of the assembly line is a continuous operation, very often more than one worker is required for this step, and the effectiveness of this procedure depends, to some degree upon the visual observation of the worker. Thus, if conveyor time is to be maintained, considerable manual labor is necessary.
The manufacture of upholstered vehicle seats has become a highly developed art, in which the upholstered elements are fitted to the rigid frame as a mechanical operation at a station on a continuous assembly line. Since the fabrics are not initially in planar condition but rather, follow the contour of the seat, wrinkles will occur depending upon the resiliency of the particular fabrics being employed. In most cases, the material is laminated to include a textile lamina, It is known in the art to remove wrinkles in relatively specific areas by manually steaming them when they are visibly detected. This has been a time consuming process and does not lend itself to in-line operation.
Briefly stated, the invention contemplates the provision of an improved means and method for rapidly steaming assembled vehicle seats, using super heated steam at a production line station wherein the operation is confined within a partially enclosed cabinet to ensure minimum loss of heat, and subject the workpiece to uniform treatment without the necessity of detecting individual wrinkles. To this end, the means includes an electrically powered heater for supplying super heated steam. The steam is conducted through manifolding to an open-sided cabinet having a plurality of manifolds with evenly spaced nozzles positioned to traverse the width of the workpiece being treated. Means is provided for collecting unused steam and condensate, and return it to the steam heater for reheating and recirculation. Separate sensor means is provided for each manifold to operate individual solenoid valves regulating steam supply. At another production line station, the back element upholstery is installed from a progressive insideout condition and simultaneously steamed as it is seated using a loop-shaped steam manifold to remove wrinkles in a progressive manner. Since substantially the entire area of the seat is subjected to a steaming operation, it is not necessary to perform visual inspection for wrinkles, resulting in elimination of a substantial amount of manual labor. Means is also provided to sense the presence of the workpiece within the cabinet to control the supply of steam to the workpiece, and stop the supply of steam when no workpiece is present. Means is also provided to maintain the steam manifolds at a constant temperature, even when the steam nozzles are inoperative.